Scientists propose finding city lights to discover alien species

Cambridge
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For decades, astronomers have utilized a variety of techniques in order to hunt down extraterrestrial civilizations. Two scientists are proposing to search for one identifiable piece of evidence: city lights.

Space agencies and non-governmental organizations have used complex methods, such as radio signals, laser pulses and Terrestrial Planet Finders, to search for planets that support intelligent extraterrestrial life. But now, an astronomy duo is putting forth the idea of just searching for lights.

The two individuals argue that over time, humans have become less detectable in the universe since the advent from radio and television broadcasts to cable and fibre optics. This could also apply to extraterrestrials.

Although the two astronomers concur that it “would be a long shot,” it would not necessitate additional resources. “And if we succeed, it would change our perception of our place in the universe,” said Loeb.

“It's very unlikely that there are alien cities on the edge of our solar system, but the principle of science is to find a method to check,” said the Princeton astronomer. “Before Galileo, it was conventional wisdom that heavier objects fall faster than light objects, but he tested the belief and found they actually fall at the same rate.”

They do conclude that the civilization would harbor Earth-like technology, which would lead to the illumination of light during nighttime. The light would be distinctive from the glare from its parent star. They add the key is to examine the change in light from an extrasolar (exo) planet during its orbit around its star.

Once identified, astronomers would then operate advanced telescopes, but the two scientists say we could use objects at the edge of our solar system. Our present telescopes, say Loeb and Turner, could view a small metropolis in the Kuiper Belt – the area that is inhabited by Pluto.